Artillery-director.



No. 876,343. PATENTED JAN. 14, 1908.

J. D. B. FULTON.

ARTILLERY DIRECTOR.

APPLICATION FILED JUNE 5,1907.

' JOHN DUNCAN BERTIE FULTON, OF NEWBRIDGE, IRELAND.

ARTILLERY-DIRECTOR.

Specification of Letters Patent.

Patented Jan. 14:, 1908.

Application filed June 5,1907. Serial No. 377,374,.

To all whom it may concern:

Be it known that I, J onN DUNCAN BERTIE FULTON, of Newbridge, countyKildare, Ireland, captain in the Royal Field Artillery, and a subject ofthe King of England, have invented a certain new and useful Artillery-Director, of which the following is a full, clear, and exactdescription, and for which I have applied for Letters Patent in GreatBritain, dated June 30, 1906; Germany, filed February 6, 1907; France,dated May 4, 1907; Belgium, dated May 15, 1907.

This invention relates to an improved artillery director forautomatically determin ing without calculations the angle of sight andespecially applicable in the case of guns firing at concealed targets.

The instrument is designed for the use of horse, field, howitzer,mountain or heavy batteries of artillery, and is intended to facilitatethe laying of guns in the correct line of fire when the target is notvisible from the gun position. The invention accomplishes this object byenabling an observer placed in a situation from which both the gunposition and the target are visible, to determine by means of theinstrument the angle of inclination to the horizontal of an imaginarystraight line joining the gun positionto the target this angle istechnically known, and is hereafter referred to, as the angle of sight.The instrument may also be used for directly observing angles of sightfor visible targets and similar angles The invention consistsessentially in providing a circle or other surface which may be placedat the observing station in a plane which contains also the gun positionand the target. The means for effecting this adjustment of the surfaceconsists preferably of a universally-jointed support, in conjunctionwith a telescope or other sighting instrument, which allows the plane ofthe circle to be successively alined in two separate directions. Inpractice these two directions will be those of the gun position and thetarget; the circle is therefore placed in a plane com mon to the threepoints, .viz. gun-position, observing station, and target. The surfaceis then rotated, still in the same plane, until a given diameter,preferably that forming the axis of the telescope or other sightinginstrument, becomes parallel to the line joining the gun position to thetarget. This is effected without further calculation by employing thepredetermined battery-angle upon a scale attached to the instrument. Theinclination to the horizontal of this diameter will then be equal tothat of the line join- .ing the gun position to the target. Consequentlythe true inclination of the latter line may be read directly from aclinometer or similar indicator attached parallel to the revolublediameter.

Upon the accompanying drawings which illustrate my invention, Figure 1is an elevation of the instrument, and Fig. 2 is aplan of the same. F 3is an explanatorydiagram.

Upon a tripod head (I/ supported on legs a is revolubly mounted a forkZ) of suitable construction which may be clamped at any desired positionby means of a locking screw Z2 or other device. A disk 0 havingcircumfercntial graduations 0 extending from 0 to 180 and back to 0, issupported above the fork Z) by a universal joint connection. In theexample illustrated, a cross (Z, (Z, (Z (Z forms this connection; twoarms (Z (Z of the cross are supported by the extremity Z1 of the forkZ), while the other two (Z (Z are pivoted in lugs 0' attached to thedisk 0. The axis of the lugs c is preferably at right angles to thediameter upon which are the graduations 0 and 180. Means are providedfor locking the arms (Z (Z (Z (Z, in their journals, as for example setscrews 0, or split ends (Z to the arms, which may be expanded bycorresponding screwsf. This provision enables the plane of the circleformed by the disk to be alined first with. the gun position and thenwith the target.

Upon the disk 0 is mounted centrally a revoluble table 9 upon a pivot gprovided with a clamping device 71 and with one or more pointers Z.- l."indicating upon the graduations c of the disk 0 the relative position ofthe two. A telescope or other sighting instrument Z having a suitablepointer in its field and with fore and back sights Z is fixeddiametrically upon the table innuediately above the pointer Zr; aelinonieter indicates the inclination of the telescope. This clinometermay comprise a lever m pivoted at m upon the table or telescope andcarrying a spirit level n. A spring 0 retracts the lever against anadjust able screw 7) furnished with lock nut p, and the relativeinclination of the table and clinometer is indicated upon a scale 1. Theextremity of the lever m may if desired carry a Vernier attachment q.

In the employment of the instrument to determine the angle of sight,when the target is not visible from the battery, a position is chosenfrom which both the battery position and the target are visible; theinstrument is there set up in the ordinary manner.

In the diagram (Fig. 3), B represents the battery position, T thetarget, and O the observing station selected. The straight line B T,representing the line of sight is obstructed by an obstacle, over whichthe trajectory B T passes. B His the horizontal line from B in thedirection of the target T, and the rectilinear angle T B H is the angleof sight which it is desired to ascertain. By reference to Fig. 3 itwill be seen that there are two angles '1 B H, and both of these arevertical. One however is a rectilinear angle viz. that between thehorizontal straight line B H and the straight line of sight B T, whereasthe other is a mixed angle being included between the straight line B Hand the curved trajectory B T. The rectilinear angle is the angle ofsight; the mixed angle is the angle of fire which is greater than theangle of sight.

The position of the observing station having been chosen the triangle TO B is solved by means of observation with the plotter; this is anecessary preliminary to the determination of the direction and rangefor the line of fire, apart from the angle of sight. This solution givesat the same time the values of the observers angle T O B, and thebattery angle T B O.

The table g, carrying with it the telescope and the clinometer, isturned so that the pointer 7c lnarks the 180 graduation on the scale 0and the table and disk are then looked together in this position by theclamp h. The set-screw b of the fork I) having been released, the latteris revolved upon the tripod-head a until the telescope is sighted uponthe gun position, the universal joint member (Z (Z being slackened topermit motion of the telescope in the vertical plane of its length. Thisjoint (Z (Z and the baseclamp b are then once more tightened. Next theconnection h between the table and the disk is released and the tablerotated upon pivot 9 until the telescope now points to the target. Itsvertical motion being in this case permitted by the memberd (Z of theuniversal joint, which is afterward locked. It is advantageous but notin practice essential that the universal joints and the axis of thetelescope should all be as near as possible to the plane of the disk 0.The table 9 is then further rotated, carrying with it the telescope andthe clinometer, until its pointer is marks upon the graduated scale 0the battery-angle T B O which has been previously determined by theobserver by the aid of the lotter.

By the oregoing operation the table has been made to coincide with theplane B O T containing the three points, battery, target and observingstation; also the telescope has been made to lie in the line 0 Tparallel to the line B T joining the gun-position to the target. Thetelescope therefore now lies at the same inclination to the horizontal OH as the line joining the gun position to the target, since parallellines lying in the same plane are all at the same inclination to thehorizontal. To ascertain, therefore, the angle of sight for the guns,2;. e. the angle of inclination of the line joining their position tothe target, there remains but to measure the inclination of thetelescope by means of the clinometer provided for that purpose. This iseffected by raising or low ering the adjusting screw 1) in order to restore the lever m to its horizontal position. When the level n indicatesthat this is the case, the reading of the vernier upon the scale qrepresents the true inclination of the line B. T, above or below thehorizontal, as the case may be.

In the employment of this instrument for the direct determination ofangles of sight and other similar angles the arms d d of the universaljoint are clamped in the fork l) and the instrument tilted upon the axisof I d d in the line desired. The inclination of this line is then readby means of the clinometer as above described.

Having thus described my invention what I claim as such and desire tosecure by Letters Patent is 1. An artillery director for determining theangle of sight, comprising a base, a disk, a universal joint by whichthe disk is mounted on the base, said joint comprising a cross twocoaxial arms of which are fitted to the base while the two other coaxialarms sup port the disk, a table revoluble on the disk, means fordetermining the relative position of the table and disk, a sightinginstrument attached to the table, and means for indicating theinclination of the sighting instrurelation to the disk, and means forindicating I the inclination of the sighting instrument.

3. An artillery director for determining the angle of sight, comprisinga base, a disk, coaxial members fitted to the base and like memberssupporting the disk, the combined members forming a universal jointupon. which the disk may tilt, a table revoluble on the disk, said diskhaving circumferential graduations, a pointer upon the table indieatingupon said graduations, a sighting instrument attached to said table, and

means for indicating the inclination of the sighting instrument.

4.. An artillery director for determining the angle of sight, comprisinga base, a disk, coaxial members supporting the disk and like coaxialmembers fitted to the base, said members forming a universal joint uponwhich the disk may tilt, means for allowing or preventing relativerotation of said base and disk, said disk having circumferentialgraduations, a sighting instrument revoluble upon the disk, a pointerindicating upon the graduation the relative position of the disk andsighting instrument, and means for indieating the inclination of thesighting instrument.

5. An artillery director for determining the angle of sight, comprisinga base, a disk, coaxial members supporting the disk and like membersfitted to the base whereby a universal joint is formed between said diskand base, means for allowing and preventing relative rotation of saidbase and disk, said disk having graduations around its circumference, asighting instrument revoluble upon the disk, a pointer indicating uponsaid graduations the relative position of the disk and sightinginstrument, and a clinometer attached to the sighting instrument.

6. An artillery director for determining the angle of sight, comprisinga base, a disk, a cross having coaxial arms .[ittcd to the base andcoaxial arms supporting the disk, said crossforming a universal jointbetween the disk and base upon which the disk may tilt, means forallowing and preventing relative rotation of the base and disk, saiddisk having circumferential graduations, 'a table revoluble upon thedisk having a pointer over said graduations, a sighting instrumentattached to the table, and means for indicating the inclination of thesighting instrument.

7. An artillery director for determining the angle of sight, comprisinga base, a disk, a universal oint between said base and disk, said jointcomprising an axis upon which the disk may tilt, a table revoluble onsaid disk, a sighting instrument attached to said table, a lever pivotedupon said table, a spirit level secured to said lever, said lever andlevel being adjustable in a vertical plane parallel to the verticalplane of said sighting instrument, and means for indicating the relativeinclination of said lever and sighting instruments when said level ishori zontal.

8. An artillery director for determining the angle of sight, comprisinga base, a revolubly mounted disk, a fork revoluble on said base, across, two coaxial arms of said cross fitting in said fork, the twoother eoaxial arms of said cross supporting said disk, a sightinginstrument revoluble upon said disk, and means for indicating theinclination of said sighting instrument.

9. An artillery director for determining the angle of sight, comprisinga base, a disk, a fork revoluble on said base, a cross, two coaxial armsof said cross fitting in said fork, the two other coaxial arms of saidcross supporting the disk, said disk having circumferential graduations,a sighting instrument revoluble upon said disk, a pointer indicatingupon said graduations the relative position of said surface and sightinginstrument, and means for indicating the inclination of said sightinginstrument.

10. An artillery director for determining the angle of sight, comprisinga base, a disk, a fork revoluble on said base, a cross, two coaxial armsof said cross fitting in said fork, a disk, lugs beneath said disk, thetwo other arms of said cross fitting said lugs, said disk havingcircumferential graduations, a table revoluble on said disk, a sightinginstrument attached to said table, a pointer upon said table indicatingupon said graduations the relative position of said disk and saidsighting instrument, and means for indicating the inclination of saidsighting instrument.

11. An artillery director for determining the angle of sight, comprisinga base, a fork revoluble on said base, a cross, two coaxial arms of saidcross :[itting in said fork, a disk, coaxial lugs placed diametricallybeneath said disk, the two other arms of said cross :litting said lugs,said disk having circumferential graduations, a table revoluble on saiddisk, a sighting instrument attached to said table, a pointer upon saidtable indicating upon said graduations the relative position of saiddisk and said sighting instrument, a lever pivoted upon said table, aspirit-level secured to said lever, a set-screw for adjusting said leverand level in a vertical plane parallel to the vertical plane of saidsighting instrument, a spring maintaining said lever pressed againstsaid set-screw, a scale upon said table, and a vernier upon said leverindicating upon said scale the relative inclination of said lever andsighting instrument when said level is horizontal.

12. An artillery director for determining the angle of sight, comprisinga tripod, a tripod-head, a vertical pivot upon said tripod head, a forkrevoluble on said pivot, a set-screw for locking said fork to saidpivot, a cross, said cross having enlarged extremities, said extremitiesbeing split to allow of expanding, coned screws entering saidextremities, two coaxial extremities of said cross fitting said fork, adisk, coaxial lugs placed diametrically on the under side of said disk,the two other extremities of said cross fitting said lugs, said diskhaving circumferential graduations a table revoluble on a pivot centralof said disk, a clamp for locking said table to said disk, a sightinginstrument attached to said table, a pointer upon said table indicatingupon said graduations the relative position of said surface and sightinginstrument a lever pivoted upon said table, a spirit-level secured tosaid lever, a set-screw with lock-nut for adjusting said lever and levelin a vertical plane parallel to the vertical 'plane of said sightininstrument, a coiled spring between said lever and said table, saidspring maintaining said lever against said set screw, a scale upon 10said table, and a Vernier upon said lever re istering upon said scale.

n witness whereof, I have hereunto set my hand in presence of twowitnesses.

JOHN DUNCAA BERTIE FULTON. Witnesses:

VICTOR F. FEENY,

CYRIL FEENY.

